1 decided on or done by personal discretion, rather than by reason: an arbitrary decision.
I am very confused. Did the words " arbitration and arbitrary"originate from the same word? If yes, then whey have they two different meaning?The etymology comes from arbiter, which has come to mean a judge.
Do do something arbitrarily is to do it basing one's judgement on one's will, rather than one's reason.
Some people use the word to mean randomly, in an aleatory fashion, determined by the throw of dice.